# physics

A sample of charcoal from an archaeological site contains 55 g of carbon and decays at a rate of .877 Bq. How old is it?

ok I am totally lost, I don't know where to start

1. 👍 0
2. 👎 0
3. 👁 892
1. The half life of C=14 is 5730 years.
A living organism has a decay rate of 15.2 decays per minute per gram.
You have a 55 gram sample; therefore,
55 g x 15.2 d/min*g = 836 d/min for the 55 g sample. That's the initial rate or Ro.

ln(Ro/R) = kt
So Ro is the intial rate from above.
R = 1 Bq = 1 decay/sec x 60sec/min = 60 decays/min. This is today's rate for the 55 g carbon.
k is a constant to be determined. How to get the constant is below.
t is the unknown. Solve for that.
k = 0.693/half-life = 0.693/5730 = ??
Post your work if you get stuck.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### chemistry

When a 8.45-mg sample of a compound containing carbon is burned completely, 18.1 mg of carbon dioxide is produced. What is the mass percentage of carbon in the compound?

2. ### algebra 2

In the formula A(t) = A0ekt, A is the amount of radioactive material remaining from an initial amount A0 at a given time t, and k is a negative constant determined by the nature of the material. An artifact is discovered at a

3. ### math

identify the variable, population and is this quantitative or qualitative The archaeological site of Tara is more than 4000 years old. Tradition states that Tara was the seat of the high kings of Ireland. Because of it's

4. ### chemistry

An unknown compound contains only carbon, hydrogen, and oxygen (CxHxOx). Combustion of 3.50G of this compound produced 5.13G of carbon dioxide and 2.10G of water A.How many moles of carbon, , were in the original sample? b. How

1. ### Exponential and Logarithmic functions

A certain material decays at a rate of 1.9% per year. The sample is 260 grams. How much will be left in 11 years? How long will it take to have only a 100g sample left?

2. ### AP Chemistry

A sample of chloroform is found to contain 12.0 g of carbon, 106.4 g of chlorine, and 1.01 g of hydrogen. If a second sample of Chloroform is found to contain 30.0 g of carbon. what is the total mass of Chloroform in the second

3. ### math

Suppose that drilling into what was once a lake bottom produces a piece of wood which, according to its mass, would have contained 5 nanograms (5 billionths of a gram) of carbon-14 when the wood was alive. Use the fact that this

4. ### History

Which archaeological dig was a Folsom kill site where bison remains were found?

1. ### statistics

It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological sites tend to lose their

2. ### Chemistry

A sample of .234g of carbon is placed in a closed stainless steel bomb with .502g of of oxygen gas. The mixture is ignited giving of carbon dioxide. How many grams of carbon dioxide should be obtained upon combustion?

3. ### math

Carbon 14 (14C) dating assumes that the carbon dioxide on Earth today has the same radioactive content as it did centuries ago. If this is true, the amount of 14C absorbed by a tree that grew several centuries ago should be the

4. ### Alg2

A piece of wood discovered in an archaeological dig was found to have lost 62% of it's carbon-14. Carbon-14 has a half-life of 5630 years. Determine it's age.